1. Field of the Invention
The present invention relates to a locating service method and, more particularly, to a method of building a locating service for a wireless network environment.
2. Description of the Related Art
LBS (Location-Based System) is mainly used for providing current geographic location or absolute position information services to a user of a wireless device. In so doing, the service provider can provide even more services and information to their users.
The LBS can be used in both indoor environments and outdoor environments; for different environments, different application technologies are utilized. For outdoor environments, GPS (global positioning system) technology is very popular, working via a link between a portable wireless device and a satellite, the satellite utilizing different positioning technologies to obtain a location and sending this location information back to the portable wireless device. For indoor environments, due to shielding effects from buildings, the GPS technology cannot be used; however, since wireless networks are increasingly popular, a locating technology that works using the wireless network has been developed.
The wireless network location-based system is built around the IEEE 802.11 environment, utilizing: a signal strength positioning method, a receiving angle positioning method, a receiving time positioning method, and a mixed time difference and receiving angle positioning method. However, indoor environments can sometimes be very complicated, and have various routes. Consequently, the receiving angle and time might have large errors, and so the signal strength positioning method offers greater accuracy.
In the technology of wireless positioning, many signal strength positioning estimation methods are available that utilize an access point. However, different environmental conditions, and other varying factors, can affect electromagnetic radiation. To improve data accuracy, the positioning system manufacturer needs to actually measure each position point to build up a signal strength database, which requires a great deal of time and effort.
Therefore, it is desirable to provide a method of building a locating service for a wireless network environment to mitigate and/or obviate the aforementioned problems.